The attachment and growth of bacteria, and other microorganisms, on surfaces as biofilms has a huge impact on mankind in numerous ways, ranging all the way from global cycling to wastewater treatment to fighting infected implants and dental plaque. This diversity is reflected in the multidisciplinary approach that is required to understand and control biofilms. The ASM Biofilms meetings series is an internationally attended conference which brings together scientists and engineers of all disciplines to discuss the latest research and exchange ideas on biofilms. The amount of biofilm literature in the medical area is markedly increasing, underlying the necessity for frequent meetings in this rapidly expanding field. Funding is requested for the support of US and International scientists attending a meeting entitled Biofilms 2009, which will be sponsored by the American Society for Microbiology (ASM), held in Cancun Mexico from November 15th through November 19th 2009. This meeting represents the fifth biofilm meeting in the series. Previous meetings have drawn ever-increasing audiences, and participant surveys demonstrate that the meetings were viewed to be highly successful and extremely relevant to the scientific community. To accommodate the increase in biofilm issues relating to medical and dental health, we have dedicated one session to "Biofilms and the Human Microbiome", two sessions to "Biofilms in Medical and Dental Infections", one session to "Biofilm Resistance Mechanisms and Control Strategies". Other sessions, such as "The Biofilm EPS Matrix", "Intercellular-Signaling in Biofilm Communities" and "Cyclic-di-GMP Signaling" although more fundamental in nature, still have great relevance for public health and towards the advancement of new techniques in controlling biofilms, whether as an infection or as an environmental reservoir of pathogens. It is the goal of this meeting to bring together the best minds and most up to date research, to educate and to foster interdisciplinary collaborations and to ultimately develop techniques to better understand and control biofilms. PUBLIC HEALTH RELEVANCE: Many infectious bacteria live in slimy colonies called biofilms where they are protected from antibiotics and disinfectants and can avoid our immune systems;however, some biofilms are useful to mankind and are used to clean up toxic waste and wastewater. They grow on our teeth as a plaque and can infect artificial implants and catheters, as well as water pipes and shower heads. The Biofilms 2009 meeting will allow us to bring together top international scientists and engineers to share their research and discuss and exchange the latest ideas and techniques to study biofilms and how to control them.